Optionally lock down athsta to a single mac address. See #210

1 files changed, 34 insertions, 15 deletions

diff --git a/athsta.c b/athsta.c
index 363f0d7..178d2cc 100644
--- a/athsta.c
+++ b/athsta.c
@@ -29,7 +29,9 @@
 
 static char name[IFNAMSIZ];	/* name of interface */
 static int verbose = 0;
+static int only_remote = 0;
 static uint8_t localaddr[6] = { 0, };
+static struct ether_addr remaddr;
 
 static u_int
 ieee80211_mhz2ieee(u_int freq)
@@ -198,7 +200,7 @@ list_stations(int s, int head)
 	struct ieee80211req_sta_info *si, *ni;
 	uint8_t *vp;
 	uint8_t *cp;
-	int len;
+	int len, print;
 
 	(void) memset(&ireq, 0, sizeof(ireq));
 	(void) strncpy(ireq.i_name, name, sizeof(ireq.i_name));
@@ -240,8 +242,16 @@ list_stations(int s, int head)
 		if (len < sizeof(struct ieee80211req_sta_info))
 			ni = NULL;
 
-		if (memcmp(localaddr, si->isi_macaddr, sizeof(localaddr)) != 0 &&
-			(!ni || memcmp(ni->isi_macaddr, si->isi_macaddr, sizeof(ni->isi_macaddr)) != 0)) {
+		print = 0;
+
+		if (memcmp (localaddr, si->isi_macaddr, sizeof (localaddr)) != 0 &&
+		    (!ni || memcmp (ni->isi_macaddr, si->isi_macaddr, sizeof (ni->isi_macaddr)) != 0))
+			print = 1;
+
+		if (only_remote)
+			print = (memcmp(&remaddr, si->isi_macaddr, sizeof (remaddr)) == 0);
+
+		if (print) {
 			printf("%s %4u %4d %3dM %4d %4d %6d %6d %-4.4s %3x"
 				, ether_ntoa((const struct ether_addr*) si->isi_macaddr)
 				, IEEE80211_AID(si->isi_associd)
@@ -284,26 +294,35 @@ load_lladdr (int s)
 int
 main (int argc, char* argv[])
 {
-    int s, i;
+	struct ether_addr *eth;
+	int s, i;
 
-    if(argc != 2) {
-        fprintf(stderr, "usage: athsta <interface>\n");
-        exit(2);
-    }
+	if (argc < 2 || argc > 3) {
+		fprintf (stderr, "usage: athsta <interface> [macaddr]\n");
+		exit (2);
+	}
 
-    strncpy(name, argv[1], sizeof (name));
-    name[sizeof (name) - 1] = 0;
+	strncpy (name, argv[1], sizeof (name));
+	name[sizeof (name) - 1] = 0;
+
+	if (argc == 3) {
+		eth = ether_aton (argv[2]);
+		if (!eth)
+			err (1, "invalid mac address: %s", argv[2]);
+		memcpy (&remaddr, eth, sizeof (remaddr));
+		only_remote = 1;
+	}
 
 	if ((s = socket (AF_INET, SOCK_DGRAM, 0)) < 0)
 		err(1, "creating socket failed");
 
 	load_lladdr (s);
 
-    for (i = 0; ; i++) {
-        list_stations (s, !(i % 10));
+	for (i = 0; ; i++) {
+		list_stations (s, !(i % 10));
 		fflush(stdout);
-        sleep (1);
-    }
+		sleep (1);
+	}
 
-    return 0;
+	return 0;
 }